1. Field of the Invention
The present invention relates to transmission shifting mechanisms, also commonly referred to gear selector mechanisms, for use in manually controlled transmissions. In particular, the present invention relates to transmission shifting mechanisms which are relatively lightweight, simple, inexpensive and are easily adaptable for direct and/or remote shifting and for left and/or right hand controls.
2. Description of the Prior Art
Manually controlled change gear transmissions of both the sliding gear and/or sliding clutch type, and the shifting mechanisms for selective shifting thereof, are well known in the prior art. In recent years there have been many improvements relating to the shifting mechanisms for such sliding gear and/or sliding clutch type manual transmissions. However, there continues to be a need to provide a relatively inexpensive, relatively lightweight, simplified shifting mechanism for establishing desired shifting movement, for providing adequate feel for the operator to establish that a correct gear has been selected and to allow relatively easy adaptation of the shifting mechanism for both direct and remote control and for both right and/or left handed control. There is also a continuing need to improve the reliability and serviceability of such transmission shifting mechanisms. Additionally, it is desirable to improve the simplicity and reliability of interlock mechanisms utilized with transmission shifting mechanisms having a plurality of axially movable shift rails therein which interlock mechanisms prevent axial movement of more than one shift rail at a given time.
The use of rectangularly cross-sectionally shaped shift rails, also referred to as flat shift rails and flat shift bars, to simplify and reduce the expense of shift bar housing assemblies is known as may be seen by reference to U.S. Pat. No. 4,273,004, hereby incorporated by reference. While the use of such flat shift rails is desirable, the means for mounting, guiding and retaining same within a shift bar housing assembly is subject to improvement.
The use of pin and/or ball type interlock mechanisms is well known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,387,501; 4,120,212 and 4,296,642, hereby all incorporated by reference. While such interlock mechanisms are functionally acceptable, they are relatively complicated and or expensive to produce, assemble and/or service.
Interlock mechanisms of the locking plate type are also well known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,929,029 and 4,132,125, both hereby incorporated by reference. While these plate type interlock mechanisms are functionally acceptable, they are not suited for all types of shifting mechanisms and/or tend to be complicated and/or expensive to manufacture and/or assemble.
Mechanisms for providing an operator with a feel for varification of proper shift rail selection when manually shifting a gear shift lever of a mechanical transmission by use of resilient yieldable means is known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,934,485 and 4,022,078 both hereby incorporated by reference. While such prior art mechanisms are suitable for certain purposes, they tend to be complicated and/or expensive to manufacture, assemble and/or service and/or do not provide the operator with a feel positively indicating correct selection in a shift bar housing assembly having three, four or more shift rails and also were not adjustable to compensate for various shift linkage assemblies which might be utilized with a given transmission.
Directly shifted transmissions wherein the transmission shifting mechanism comprises a shift lever or the like which is mounted directly in a tower assembly mounted to the transmission housing and wherein the transmission shifting lever directly engaged the shift rails of the transmission shift bar housing are well known in the prior art as may be seen by reference to above mentioned U.S. Pat. No. 4,273,004. Remotely controlled transmissions wherein gear changing is controlled by a remotely located master shift lever by means of a linkage assembly are well known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,489,028 and 4,275,612, both hereby incorporated by reference. The prior art transmission shifting mechanisms have been somewhat unsatisfactory as the conversion thereof from a remotely controlled to a directly controlled, or vice versa, shifting mechanism was often complicated, expensive and required the substitution of a large number of parts.